Bearing and method of making same



Patented Apr. 8, 1930 UNITED STATES RALPH L. SEAIBURY, OF TOLEDO, OHIO, ASSIGNOR TO DELCO-REMY CORPORATION,

PATENT OFFICE ANDERSON, INDIANA, A CORPORATION OF DELAWARE BEARING AND METHOD OF MAKING SAME N'o Drawing.

This invention relates to bearings of ranular structure, and particularly to sel -lub ricating bearings, and to a method of making same.

An object of the invention is the provision of a bearing of this class which is provided with a metallic bearing surface. A further object of the invention is the provision of such a bearing with a metallic bearing surface of a porous nature adapted to permit the seepage of oil therethrough from the interior bearing structure during use, whereby an automatic lubricating of the bearing surface is effected. Another object of the invention is the provision of a simple and efiicient method of makin bearings of this character. Another object o the invention is to so treat the porous structure of the bearing that after impregnation of the same with oil a more eflicient retaining of the oil Within the hearing will be efiected than would otherwise be the case. Other objects and advantages of the invention will be apparent from the following detailed description thereof.

In the preferred and practical operation of my method in the manufacture of bearings, I employ a mixture of substantially 82% copper powder, 9% tin powder, 3% lead powder, and 6% graphite powder, although the particular composition employed is not material to the essential features of the invention and may therefore, be changed or varied materially. These ingredients, which are preferably but not necessarily of powder form and of a fineness to enable them to pass through, a screen of about 150 mesh, are

thoroughly mixed together and then subjected in a mold to an initial shaping pressure of about twenty tons per square inch'. This initial shaping gives the molded material the general but not the exact shape and size desired for the finished article. The molded article is then subjected to a baking action-in a temperature of about 750 C. by which it is strengthened and rendered somewhat malleable and distinctly metallic. The temperature should not be sufficiently high, however, to effect a general fusing together of the ingredients forming the article.

After the baking operation the article is Application filed July 3, 1926. Serial No. 120,541.

finished form. While it is preferable to electroplate the article after baking, these operations may be reversed if desired. Therefore, where bakin and electroplating is called for by the claims, either operation may be first.

The mold for the original forming of the piece should be slightly smaller than the outside diameter of the re-shaping die, soas to permit an easy insertion of the same into the die, and should be somewhat longer than the finished article to permit a compressing ofthe material of the article into its final or finished form. If the bearing is of'hollow cylindrical or sleeve form its internal diameter should be slightlygreater than the core or plug portion of the die fitting therein, thus facilitating an easy mounting of the article in the die preparatory to re-sh'aping.

After the re-shaping operation, the article is forcefully ejected from the die while it is in close contact with the sides of the die and its core member, so that the frictional coaction of the electroplated surface or surfaces of the article with the respective portions of the die will cause a burnishing and polishing of the plating surface, thereby removing any slight irregularities or roughness from the surface thereof and at the same time giving the article a. finished and pleasing appearance.

The compressing of the internal granular structure of the article after the oil impregnating operation seems to partially seal or close the cells or pores containing the oil and thereby more efi'ectually retain the oil in the article than is possible without such compressing. At the same time the compressing of the metallic coating or plating increases the density thereof and renders it less porous to the passage of oil therethrough. It will, therefore, be apparent that while the metallic coating itself will materially facilitate the retention of oil within the body of the article over what would be possible if the plating were omitted, the compressing of the plating as well as the compressing of the a-nular structure of the article materially 1 acilitates or enhances the oil retaining feature.

The electroplating of the hearing or Wear surface of the granular bearing member and the compressing of such plating gives a hard gloss wearing surface which at the same time is su ciently porous to allow a slight seepage of oil from the body of the bearing through the plated surface. In this way, there is sustained a good lubricating effect. In addition to the bearing being provided with a metallic wear surface that is lubricated from within the bearing body, it also enables the granular body structure of the bearing to be composed of less ex ensive materials than where the granular bo y itself is to form the bearing surface. For instance, instead of usin the more expensive compound enumerated a ove, a aphite and iron mixture maybe used, a suitable mixture for such purpose being 90% powdered iron with 10% powdered graphite.

Such-a composition would be sufliciently p0 rous for the absorption of oil while a brass or bronze electroplating would answer all the re uirements of an efiicient bearing surface. aving thus described my invention, what I claim as new and desire to secure by Letters Patent is: 1. A bearing having a granular porous body portion and an electroplated bearing surface tending to seal the pores.

2. A hearing having a granular porousbody portion and a compressed electroplated bearing surface tending to seal the pores.

3. A hearing having a granular body portion composed ofgrains only partially fused together and a metallic bearing surface intimately cohering therewith. I 4. A hearing having an oil impregnated ranular body structure and a porous metalic coating for said structure.

5. A bearing having an oil impregnated granular body structure and an electroplated earing surface through which the oil may see 4 6 A bearing having an oil impregnated granular body structure and a compressed electroplated aring surfacesufliciently porous to permit a slow seepage of oil there- ,through. 7

7. A bearin having a granular body structure composed of grains onl partially fused together and an electroplate coating entirely engloin the body structure.

ing from loose granular materlals consisting earing having a granular body. structure composed of grains only partially the internal structure of the body and the coating, and causing the body to have a frictional ejecting coaction with the die walls to burnish the coating.

11. The method of making a bearing, consisting in shaping loose granular materials under pressure to form a granular body, baking to a temperature to cause incipient fusion between the particles composing'it, and electroplating the body to form a metallic hearing surface.

12. The method ofmaking a bearing consisting in shaping loose granular materials under pressure to form a granular body, baking to a temperature to cause incipient fusion between the particles composing 1t, and electroplating the body to form a metallic bearing surface, and subjecting the electroplated article to a compressing and shaping pressure.

13. The method of making a granular bearin shaping under pressure the materials forming the bearing, baking the sha ed article to a temperature to cause incipient sion between v the particles composing it, electroplating the baked article, im re ating the article with oil, and then sub ect1ng the article to a compressin force.

14. e method of making a granular bearing from-loose granular materials consisting in shaping under pressure the materials forming the article, baking the shaped article to a temperature to cause incipient fusion between the particles composing it, electroplating the bearing surface of the article, and impregnating the article with oil.

15. The method of making a granular bearing from loose granular materials consisting in giving a reliminary shape to bodies formed from t lie granular materials, baking the shaped article to a temperature to cause incipient fusion between the particles composing it, electroplating the baked article, impregnatinglthe article with oil, and then compressing t e article to give the same a finished form and to render the anular body and electroplatin of greater ensity.

16. The meth of treating porous nular bearings to render them self-lubrlcating and to tend to retain the lubricant therein, consisting in electroplating the bearing, then impregnating the bearing with oil and then subjecting the bearing to e compressing ressure to increase the density of both the ody structure and electroplating of the bearing whereby the oil is partially sealed or imprisoned therein.

- In testimony whereof I have hereunto signed my name to this specification.

RALPH L. SEABY. 

